The present invention relates in general to pile fabric, and more particularly to knitted elastic lock pile fabrics. The invention is concerned with a unique elastic knit fabric having pile loops on its back surface which are aligned in rows along the linear axis of the fabric and across the transverse axis of the fabric, the loops being disposed in standing relation with the openings in successive transverse rows being canted in opposite directions so that the fabric may be used as the loop portion of a hook and loop fastening system.
Heretofore, it has been common to produce elastic knit fabrics on generic warp knitting machines such as tricot and raschel machines. More recently a number of specialized, narrow width machines have been developed especially for making narrow tapes and elastic webbings. These machines, with names such as raschelina and crochet, are essentially small versions of raschel machines and they incorporate various needle types such as spring beard, latch and compound needles. Elastic fabrics made on these machines usually contain various normal textile yarns along with elastomer yarns such as rubber, latex or spandex. The knitted structure allows for considerable lengthwise extension when stressed and the elastomer gives the recovery to the fabric upon relief of stress.
The purpose of the present invention is to make a knitted elastic webbing that has a loop pile surface on one side. The loops can be regulated in height and spacing and are locked in the fabric so that they may serve as the loop portion of a hook and loop fastener. The pile loops are locked into the knitted stitch at each end so one loop will not rob thread from the adjacent loops and will return to its knitted shape and size upon removal of any stress it has undergone. The pile loops may be made from various types of yarn for special effects. For a pile fabric to serve as a fastener member it is desirable that the loops have considerable rigidity; thus, monofilament yarns are preferred but yarns such as bi-filament, tri-filament or various multi-filaments can be used for the pile. The body of the fabric can be made from any material such as nylon, polyester or polypropylene depending on aesthetic and technical characteristics desired in the finished product. Any type of elastomer can be used such as rubber, latex or spandex of suitable denier for the machine used.
A unique feature of the fabric of the present invention is that it is particularly suitable for providing a narrow knitted fabric providing an elastic band or fabric zone that is receptive to the hook portion of a VELCRO.TM. hook and loop fastening system, to provide a hook and loop fastening system for health care products, such as incontinent garments where hook and loop fastening is desired.